Express your answer as a mixed number simplified to lowest terms. $7\dfrac{4}{9}-5\dfrac{3}{5} = {?}$
Answer: Find a common denominator for the fractions: $= {7\dfrac{20}{45}}-{5\dfrac{27}{45}}$ Convert ${7\dfrac{20}{45}}$ to ${6 + \dfrac{45}{45} + \dfrac{20}{45}}$ So the problem becomes: ${6\dfrac{65}{45}}-{5\dfrac{27}{45}}$ Separate the whole numbers from the fractional parts: $= {6} + {\dfrac{65}{45}} - {5} - {\dfrac{27}{45}}$ Bring the whole numbers together and the fractions together: $= {6} - {5} + {\dfrac{65}{45}} - {\dfrac{27}{45}}$ Subtract the whole numbers: $=1 + {\dfrac{65}{45}} - {\dfrac{27}{45}}$ Subtract the fractions: $= 1+\dfrac{38}{45}$ Combine the whole and fractional parts into a mixed number: $= 1\dfrac{38}{45}$